MEDIUM CVSS 6.5
Published: 2026-05-13

CVE-2026-31156

openplcproject openplc_v3_firmware Security Advisory (CVE-2026-31156)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-31156 impacting openplcproject openplc_v3_firmware. Evaluated with CVSS Base Score of 6.5 (MEDIUM).

Original NVD Description

Source: NIST NVD
A path injection vulnerability exists in OpenPLC v3 (2c82b0e79c53f8c1f1458eee15fec173400d6e1a) as the binary program compiled from glue_generator.cpp does not perform any validation on the file path parameters passed via the command line. The user-controlled input parameters are directly passed to the underlying file operation functions (fopen/ifstream/ofstream) for file reading and writing. An attacker can exploit this vulnerability by constructing a malicious path to read arbitrary readable files.

📊 CVSS v3.1 Metric Breakdown

Attack Vector
Network (AV:N)
Exploitable remotely across internet boundaries
Attack Complexity
Low (AC:L)
No specialized conditions required
Privileges Required
Low (PR:L)
Standard user access required
User Interaction
None (UI:N)
Zero human interaction required
Scope
Unchanged (S:U)
Confined to same security context
Confidentiality
High (C:H)
Total information disclosure
Integrity
None (I:N)
No system modification impact
Availability
None (A:N)
No system availability impact

🎯 Affected Versions Matrix

Affected Product openplcproject / openplc_v3_firmware
Affected Versions 2024-03-09
Weakness Enumeration CWE-22

Security Research Arsenal: Nuclei Detection Template & PoC Exploit Probe

High-Intent Research Tool

Ready-to-use security scanner signatures, active verification probe skeletons, and remediation playbooks for CVE-2026-31156 impacting openplcproject openplc_v3_firmware.

⚡ Nuclei Detection Template (YAML) cve-2026-31156.yaml
id: cve-2026-31156

info:
  name: openplcproject openplc_v3_firmware - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: medium
  description: |
    Automated signature & scanner for CVE-2026-31156 affecting openplcproject openplc_v3_firmware.
    Evaluation: A path injection vulnerability exists in OpenPLC v3 (2c82b0e79c53f8c1f1458eee15fec173400d6e1a) as the binary program compiled from glue_generator.cpp ...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-31156
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
    cvss-score: 6.5
    cve-id: CVE-2026-31156
    cwe-id: CWE-22
  tags: cve,cve-2026-31156,openplcproject,openplc_v3_firmware,medium

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "openplc_v3_firmware"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-31156.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-31156
# Target: openplcproject openplc_v3_firmware | CVSS: 6.5 (MEDIUM)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-31156 (openplcproject openplc_v3_firmware)...")
    headers = {
        "User-Agent": "CyberVault-Audit-Scanner/2.0",
        "Accept": "*/*"
    }
    try:
        r = requests.get(f"{target_url.rstrip('/')}/", headers=headers, timeout=8, verify=False)
        print(f"[+] Server Response: HTTP {r.status_code} | Server Banner: {r.headers.get('Server', 'Unknown')}")
        if r.status_code < 500:
            print(f"[!] Target reachable. Verify version against openplcproject openplc_v3_firmware scope (2024-03-09).")
        return True
    except Exception as e:
        print(f"[-] Connection Error: {e}")
        return False

if __name__ == '__main__':
    url = sys.argv[1] if len(sys.argv) > 1 else "http://localhost:8080"
    verify_vulnerability(url)
🛡️ Quick Patch & Remediation Script (Bash) patch_cve-2026-31156.sh
# Recommended Remediation & Patching Commands for CVE-2026-31156
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install openplc_v3_firmware 2>/dev/null || \
sudo dnf upgrade openplc_v3_firmware 2>/dev/null || \
sudo yum update openplc_v3_firmware

# 2. Inspect installed package versions for vulnerable scope:
dpkg -l | grep -i openplc_v3_firmware 2>/dev/null || rpm -qa | grep -i openplc_v3_firmware

# 3. Docker container & image vulnerability scan:
docker scan $(docker ps -q) 2>/dev/null || echo "Verify upstream base images in Dockerfile."

🛡️ Remediation & Security Action

  • Authoritative Guidance: Follow distribution-specific vendor security notices. Advisory status and package patches vary by distribution release.
  • Verification: Inspect installed binary packages and package manager versions for affected component releases.
  • Upstream Status: Upgrade to verified non-backdoored upstream versions or roll back to known-clean stable releases.
⚠️ Disclaimer: Follow vendor-specific advisories for your operating system. CyberVault does not fabricate unsupported remediation scripts.

🔗 Verified Technical References

Authorities
  • No records filed in this category.
Distributions
  • No records filed in this category.

❓ Frequently Asked Questions (FAQ) & Remediation Guide

How do I fix CVE-2026-31156 in openplcproject openplc_v3_firmware?

Review vendor-specific security notices and update openplcproject openplc_v3_firmware packages to the latest patched release immediately. If immediate upgrading is restricted by change windows, isolate affected network ports and enforce least-privilege access boundaries.

Is there an active exploit or public PoC for CVE-2026-31156?

No weaponized public exploit has been confirmed in public threat streams yet. Continuous surveillance is active across GitHub and security feeds.

What is the CVSS 3.1 severity rating and impact for CVE-2026-31156?

CVE-2026-31156 is classified with a CVSS 3.1 Base Score of 6.5 (MEDIUM). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
6.5
MEDIUM SEVERITY
CVE ID CVE-2026-31156
Weakness CWE-22
Vendor openplcproject
Product openplc_v3_firmware
Published 2026-05-13
Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N